Sleep: Turning Experience Into Knowledge Since Ever

Toddlers are busy people. All you need do is spend twenty minutes with one of these energizer miniatures and you know you’re in the company of a source of energy that seems inexhaustible. At least it does until the little guy hits the deck mid-step for a nice long nap. Turns out that even when they’re asleep, these indefatigable guys are still busy.

A new study shows that toddlers use their sleeping time to turn their experiences into knowledge. The process works something like this: Your toddler spends an exciting time at the grocery store with you telling her the name of each item you put into your cart. By the time you make it through the entire store, you’re more than ready for the ride home. And your toddler is sound asleep in her car seat. While said toddler is asleep, she is not just dreaming about the time spent with you. Her brain is busy categorizing the experience and turning the fun you’ve just had into knowledge.

This discovery is based upon work done by researchers who studied their interactions with 9- to 16-month olds. The parents and toddlers were invited to a training session in which the toddlers were repeatedly shown images of objects while hearing the name of the object. The names were fictitious and the objects were intentionally ones that could be categories by proportion, color, or other details. Objects that were belonged to the same category by shape were always given the same names. EEG measurements were recorded during this process.

After the interaction with researchers, one group of toddlers spent the next hour or two sleeping while another EEG was recorded. The other group stayed awake and went for a walk. Both nappers and non-nappers then had another learning session. EEG recordings were made for both groups as the little guys went through the same combinations as the first learning session, as well as being exposed to new combinations.

The results? All of the toddlers were able to recognize the original objects. The nappers were able to make connections between the objects by category while the non-nappers were not. Examination of the EEGs during sleep showed brainwaves known as sleep spindles. It was found that the experience was taken to the next level during these spindles. In fact, “the greater an infant’s spindle activity, the better it can assign category names to new objects after sleep,” according to the researcher Manuela Friedrich.

All in all, the study raises the question of whether or not this experience-to-knowledge link is made by older children and adults. Maybe it’s not so silly for kindergartners to take a nap mid-day. Maybe nap breaks while studying could help the study process in adults. It’s a question that certainly deserves some attention!